Odd ticking noise from fans in new system

[pgamble]

Hi guys

Really frustrating problem.

I have a new build based on the following :
CM690II Advanced Case
Corsair HX850 PSU
Sabertooth motherboard
i7 950 at 4Ghz with Megahelms and two Akasa black fans (push / pull)
EVGA GTX580
6GB Corsair Dominator at 1603Mhz / 8-8-8-24
NZXT2 Fan controller
Vertex 2e 120GB
WD SATA 600 1TB
Samsung SATA 300 1TB
D2X sound card

She's fast, fairly cool running and aside from one fan, really quiet.

My issue is that the case supplied CM 140mm front intake makes a buzzing / ticking noise when in the case.
If I cut the power to this fan with the NZXT there is only the quiet whooshing of air ... no other noise at all - so the rear exhaust (an FD120), the case bottom intake (Sharkoon SE 120mm), the case top (140mm CM) and the two Akasa Blacks on the CPU cooler make no noise except air movement. Indeed the GTX580 make no noticable noise at all.
The microsecond you start the front fan ... the buzzing / ticking starts. The noise is consistent and is not changed by fan speed.

If I power up the fan outside the case ... not noise.
I put rubber grommets on the mount screws to cut resonance when I put it back in ... but the sound is still there ... very odd.

I had an old 120mm CoolTech (1000rpm) .. the CM690II ADV can take 140 or 120 at the front. This when attached to the same power is silent.

I figured it must be the CM fan then.

I then got an FD140 and replaced the CoolTech with that ... this has the same buzzing / ticking noise as the CM fan. It is almost as if the noise is thrown to the middle or back of the case as well. It is very difficult to link it to a particular fan without shutting each fan down as I did.
Again, like the CM140 fan ... there is no noise when it is powered up outside the case ... only when attached ... even with rubber separating grommets between the fan and the case.

I'm really frustrated. I've gone back to the CoolTech until I can find out the cause.

What can cause a slow buzz or ticking noise (the latter is probably a better description) that appears to be linked to using a 140mm fan in the front of this case but isn't specific to a given fan and doesn't happen with a cheap 120mm fan ?

Any help / suggestions, hugely appreciated.

Best regards

Paul.

 

[KLin]

Kinda catchy.. Snape, snape, severus snape.

Sorry, couln't resist . I remember having an annoying ticking sound on a case fan that exhausts fan from the top. Turns out a small plastic notch was hitting the blades and causing the noise. After a little work with a dremel, it's been quiet.

 

[pgamble]

Thanks.

As mentioned, this is definitely related to the front intake and is specifically tied to a 140mm fan being fitted rather than a 120mm fan.

Anyone got any checks I can do to ascertain where the noise is coming from. There are no loose wires around the fan. The fan makes no noise when connected outside the case. A 120mm fan in it's place makes no noise ... and two different 140mm fans make the same noise .... a tick tick tick.

Very odd and very frustrating.

Paul.

 

[Soccerman06]

Spin the fan with your hand and see if it makes noise and try to locate where it comes from. Use a razor or dremel to clean it. It could also be a bad fan or its in the process of dying, in which case, your screwed.

 

[pgamble]

Hi guys

Sorry about this ... I have shown that there are no obvious fan clearance issues.

This is my frustration. It is a front fan and it is very clear of things and easily accessible.

It must be the fan's interaction in some other way ... that is why I'm frustrated ... because none of the usual things are happening.

Is there something about two different brands of 140mm fan that interact with a system differently from your average 120mm fan which doesn't cause a problem ? This is a slow repetitive ticking that doesn't change with fan speed. It starts the moment the fan goes on at it's lowest setting and stays the same even at full speed. This is why it can't be obstruction related.

Paul.